I've written about matchbox labels in this space before (see here and here) because it's incredible that there are so many, so varied and so small. The latter is key. How do you fit so much into such a tiny space?

I thought I was cured. About a decade ago, I vowed to put a cap on my bottle cap collection, after being injured in the line of duty (an embarrassing story I’ve recounted way past its expiration date, I’m afraid). I was through with mining for small objects, but recently started “pinning” a few...